EKPP Ressel (August 2003)

[Pierre Farrugia]

<font color='#0000FF'>Hello WL,

As I said before I always gather informtion and then I can decide weather to use it or not. I am TDI adv. trimix qualified so I ahve the basics there and so I can judge what is normal profile to very aggresive diving. What I want to determaine is what is normal, many divers consider as normal and not me doing too much un nesessary deco.

Why don't you tell us more about this formula, of which you always mention but never discussed and what backs this up. I neer heard of this yet so an interesting new info. Also everything I hear here I always compare it to my thrusty Proplanner &nbsp;

Michael what you use for deco planning? Do you use a special programme? Is it available to public or something experimental?

Regards

Pierre

[db8us]

Originally Posted by [b

Quote[/b] (Pierre Farrugia @ April 20 2004,17:24)]Michael what you use for deco planning? Do you use a special programme? Is it available to public or something experimental?

We currently use JPLAN on the PALM and then modify the profile ourselves.

Usually we take average depth and estimated bottom-times and then we first discuss what we think might be the total decotime.
Then we run it against the software and i usually draw a curve.
If that looks to long/shallow, we shorten it and we also pull the deep-stops deeper to 80% of max.pressure.
We also usually can cut an hour extra on the long dives when we use a habitat, since we go on O2 at 9m.

Michael

[Mark Chase]

Personaly I plan a dive on a 1.4 PP02 at max depth. This meens I will be doing most of the dive at arround 1.3ppo2 due to the fact wrecks stick up a bit and the interesting things are not always on the bottom.

As said I will have a gas that is breathable within 5m of max depth and this will either be my first deco mix or a safety bottle. Then I will have a rich deco mix of 80%.

Personaly I dont mind lugging the gas about and dont find the task loading a problem.

Having planned the gas I wll plan the dive on Decoplanner using a 20/80GF with the usual + and - depth / time bail outs.
On the ZHL16B useing using Ascent in run time seting.

Then I will do the dive folowing the VR3 on 0 safety setting. and a 3m per min ascent rate with a 5min ascent from 6m after the VR3 has cleared.

I will be in the water much longer than te DIR boys but I feel good and dont mind the hang as long as it dosent go over 90mins.

ATB

Mark Chase

[Mark Chase]

Originally Posted by [b

Quote[/b] (wetlettuce @ April 20 2004,12:01)]

Originally Posted by [b

Quote[/b] ]Mark, the guys are DIR divers indeed, but not GUE trained (or at least at the time) and were not running GUE profiles.

We both know who drew up those profiles. I met him on the GUE stand as this years LIDS

Originally Posted by [b

Quote[/b] ]Although it is good to learn from, we should not associate this with GUE's deco education or policy.

Running their profile using the Tech1 system where are the errors? They claimed to have had the profiles checked and cleared at the time. Using Tech1 profiles can you indicate the error in their plan?

Originally Posted by [b

Quote[/b] ]As I said before a standard single deco gas dive of 54 mtrs for 40 mins is a runtime of around 103 mins using 21/35 and a single deco gas. Using o2 would decrease this to around 90 minutes, again comparable with a 30/90 profile, perhaps 30/100.

Nothing wrong with the run times you offered are within 30/90 30/100 profiles. but the gas mix, depth and bottom time are different from that being discussed so its not particularly relevant.

Originally Posted by [b

Quote[/b] ]What I do notice is when using the hypoxic mixes and O2 then the profiles no longer follow 30/90GF. But I believe this is where the difference between algorithm and reality occur. The Pn2 of the gasses we use is very low and it is nitrogen which causes the bend, agreed?

Hmmmmmm last two bends I was associated with were He bends so I wouldn’t be too confident about that. Cant remember the specifics of the first one but the second was a 65m dive for 45mins using 17/40. He was using 32% and 100% for deco and was actually suffering from the bend whilst on the 6m stop. There were 8 divers running the same profile on the same gas and he was the only bent diver. &nbsp;

Skin blotches total loss of function in left arm and some one sticking knitting needles into his elbow joint type symptoms

Sucked 02 on the boat for two hours job done. No recompression treatment sought. This was after 5 days diving 60m + wrecks.

Originally Posted by [b

Quote[/b] ] Helium is a faster gas and is dealt with by deeper stops. The software will penalise you for the lower Po2 but not credit you properly for a higher PHe.

Helium is a faster gas in both directions. IE it on gasses fast and it off gasses fast. But fast is relative. If it takes 90mins to off gas the lower level of on gassed Nitrogen after a 40min bottom time and it only takes 90 mins to off gas the much larger percentage of fast He after the 40min dive then He can still be described as a fast gas. Te present arguments lay in the area of how fast.

I agree deep stops with He are a must. Having said that I was always taught to get on to Nitrox ASAP because it was the High Po2 that flushed the He out of the system quickly and that the deep stops just prevented the bend.

Originally Posted by [b

Quote[/b] ]A comparison between the computer profiles is interesting. Despite a pn2 of 2.8 using 21/35 and a much lower pn2 of 1.79 for 17/55 the deco on the computer increases by 19 minutes. Does that make sense? Not to me it doesn't. The algorithms do not treat helium with the credit it deserves and actually penalises you for using a higher helium content even though this drastically reduces your nitrogen uptake. Whether you say that is voodoo or dangerous or what is not my concern. There is little or no science behind the algorithm when concerning helium, and it is rapidly being proven that they've got it wrong.

Yes, but remember GUE's/DIR's Decoplanner does exactly the same as all the others so they haven’t had the courage of their convictions yet.

The revelation that He may be used to treat the Bends (50/50mix) is perhaps the first step in independently proving the DIR theory. If it does turn out to be the new best thing then expect to see me first in the queue for the 50/50 deco mix and the VR3 upgrade.

As others have said I will wait on the sidelines like the 40 year old father of two that I am and let the young guns take the big risks. What I do now works for me but with the right supporting data I am open to suggestion.


ATB

Mark Chase

[/quote][quote]

[And]

<font color='#000080'>Hi

OK, as far as I know, because I wasn't there, they asked John what he would do and he told them, from his vast experience and knowledge of his own personal limits. They did not 'check' or 'approve' anything. Comparing the profiles to Tech1 there is quite a bit of difference. The deco above 21 mtrs itself is short by 15 mins on the first dive and 13 mins on the second dive. If they had used O2 as well as 50% then the profiles would be OK. The deep stops also start much shallower. On the first dive Tech1 profiles would be stopping around 42 mtrs and on the second dive around 36 mtrs meaning about another 3 or 4 mins runtime.

Regarding the supposed he bend. So you don't think that an increase in pn2 was to blame? Moving from 17/40 to 32% nitrox at 39 mtrs is quite a jump IMHO. 2.3 pn2 to 3.4 pn2. How can you ever know exactly which gas is causing the bend? Sounds like the usual helium is devil gas story.

In bubble theory it is also the 'inspired' gas which helps the offgassing process. Changing to a relatively low po2 content nitrox which is high in nitrogen may not neccessarily help, especially as you are inspiring nitrogen all the way to the surface when using 80%. One reason to use o2 as a final clean up gas.

Kindest Regards

Andy

[db8us]

Just to clear my position:
Nobody should be pushed to make th deco shorter.
I am just against adding too many safety-factors and then people have no clue, when they could be out of the water if shit hits the fan !

I still remember Garrett Weinbergs death, were Claudia pulled 1 hour of deco, where she could have surfaced...

[bang-on]

<font color='#0000FF'>

Originally Posted by [b

Quote[/b] (db8us @ April 20 2004,17:40)]We currently use JPLAN on the PALM and then modify the profile ourselves.

michael,
i would use the proplanner and v-planner as well as the dive planner in the vr3,the vr3 and a back up computer then dive with me both as a record of the actual dive which is never going to be identical to the planned but also as an active profile adjuster and a way to calculate stops with gas changes and cc,o/c,scr variables.
also i would think it benificial to have a record that can be looked at by hyberbaric staff to aid and administer the treatment based on an accurate dive profile and gas profile.
do you record your actual profiles when testing the effects of richer he mixes and are these looked at by the university?
if so what do you record the profiles on.
i gather from your post you have not used a vr3 personally so may offer you the  use of one for a period and you can see what you think.

cheers
barrie

[Pierre Farrugia]

<font color='#0000FF'>Hello all,

Michael you are spot on, what I want to conclude is, with the programme I use, I am putting in too much safety? I dive it with 10% safety and 10% microbubble formation on Proplanner, as I saw tought from my Inst, is this the normal or I am adding too much safety? An other thing I like is, to have the basic profile for the dive, and then if sh;t happens I can get out of the water but if I have a normal dive I can do a safety stop as much as I want!

Mark, what safety you use on proplanner?

Regards

Pierre

[Mark Chase]

Originally Posted by [b

Quote[/b] (Pierre Farrugia @ April 21 2004,14:20)]Mark, what safety you use on proplanner?

Regards

Pierre

0 safety settings. Its prety conservitive.

On the VR3 I run it on 0 safety and then I know the minimum and I add slow ascents and 5min ascents from 6 to pad the profile.

I dont like proplanner profiles so I only use them as comparison. I stick to Decoplaner for actual back up tables on 20/80GF

As De8us said, there are times when too much deco can be dangerous. &nbsp;I will have a 100/100GF 0 safety bail out table and if it hits the fan I will use that to get out ASAP and risk a Type 1

Never had to use it till now but I have ran the minimum on the VR3 when things got a little dodgy (see my Duke dive report) but thats about it.

ATB

Mark Chase

[Mark Chase]

Originally Posted by [b

Quote[/b] (wetlettuce @ April 21 2004,10:58)]Regarding the supposed he bend. So you don't think that an increase in pn2 was to blame? Moving from 17/40 to 32% nitrox at 39 mtrs is quite a jump IMHO. 2.3 pn2 to 3.4 pn2. How can you ever know exactly which gas is causing the bend? Sounds like the usual helium is devil gas story.

In 20 years time when you have as much diving experiance as the chap who got bent I have no doubt you will be able to tell the diferance like he can.

You dont fix a Nitrogen bend breathng atmospheric presure 02

As far as the jump is concerned Andrew and I looked at this with Mark Elliot and it was right on the edge of acceptable using his new counter defusinon calculator. It should also be said that I have dived a lot deeper with more 02 and more He in the mix and switched to 32% without incident on deco. &nbsp;

If an old fat git like me can get away with it I would sugest a majority of other divers would too. HE in the deco mix is a new thing. Switcing from back gas to 32% has been going for years without aparent incident.

ATB

Mark Chase